12 March 2012
Psyco is unmaintained and dead. Please look at PyPy for the state-of-the-art in JIT compilers for Python.
16 July 2010
Python 2.7 is unsupported so far. Anyone interested in porting Psyco to it is
welcome. I started the work in a branch
but it needs finishing.
4 March 2010
On Mac OS/X "Snow Leopart" you don't actually need to recompile
Python yourself, but just use the following command line
(thanks Elvis Pfützenreuter):
defaults write com.apple.versioner.python Prefer-32-Bit -bool yes
8 December 2009
Just for reference, Psyco does not work on any 64-bit systems at all.
This fact is worth being noted again, now that the latest Mac OS/X
10.6 "Snow Leopart" comes with a default Python that is 64-bit on
64-bit machines. The only way to use Psyco on OS/X 10.6 is by
recompiling a custom Python in 32-bit mode (on Linux, see
or here for example).
20 January 2009
Michael Foord contributed a Windows binary for Python 2.6 (as well as
Psyco 1.5.1 binaries for Python 2.2 and 2.3). Get them
directly from voidspace.org.uk.
7 January 2008
Thanks Chaiwat Suttipongsakul for contributing a Win32 binary for
Python 2.5! Get it from the
16 December 2007
Released Psyco 1.6 with Intel MacOS/X support, thanks to Gary Grossman. Also includes a couple of general bug fixes (Windows binaries: contribution welcome). From this version onwards we no longer support Pythons older than 2.2.2.
- 28 September 2007
Sorry, the file at http://codespeak.net/~arigo/psyco-mactel.diff was
missing for a while. It's back now.
26 September 2007
Psyco was ported to Intel Mac OS/X by Gary Grossman. I will review and
check in his code; in the meantime the patch is available there:
2 May 2007
The snake machine is down - died of too much PyPy - so the
snapshot of the latest sources is now at
See installing from sources.
26 January 2007
Fixed a bug triggered by Python 2.5's bytecode optimizer. Users of 2.5
should either avoid
psyco.profile() or upgrade to the
8 December 2006
Got a Win32 binary for Python 2.4. See
Contributed by ffao.
29 November 2006
Fixed the corrupted Win32 binary for Python 2.5. See
Thanks again to Jon Foster. The corruption of binary files attached to
SourceForge's patch tracker seems to be a known problem...
(Note that as far as I can tell, mirrors make take a little while
before they have got the updated version. The correct version has an MD5
sum of 14194043a1488c7a33ad7f4ba7c2171c.)
27 November 2006
The Win32 binary installer seems to be broken :-(
Updates to follow...
22 November 2006
Got a Win32 binary for Python 2.5. See
Thanks Jon Foster!
21 November 2006
Released Psyco 1.5.2 with Python 2.5 support. (Windows binaries: contribution welcome.)